Electroviscous fluids containing metal sulfonate functional organopolysiloxanes

Abstract

The present invention relates to an electroviscous fluid comprising the dispersion in an electrical insulating fluid of an organopolysiloxane having at least one metal sulfonate group in its molecule. The electroviscous fluid of the present invention can further comprise a polyether. The electroviscous fluid of the present invention does not wear or abrade surrounding equipment, is thermally stable, and that has a large electroviscous effect (yield value) and an excellent dispersion stability.

That which is claimed is: 
     
       1. An electroviscous fluid composition comprising: (I) an electrical insulating fluid selected from the group consisting of dibutyl sebacate, fluorine oils, and silicone oils; and   (II) an organopolysiloxane compound having the unit formula: ##STR7##  wherein R 1  is C 1-20  alkyl or aryl; R 2  is C 1-20  alkylene; X is a monovalent or divalent metal ion; l, m, p, and q are zero or greater than zero; and n is 1 or 2; with the proviso that p and q cannot simultaneously be zero.   
     
     
       2. A composition according to claim 1, wherein the silicone oil is a diorganopolysiloxane oil. 
     
     
       3. A composition according to claim 2, wherein the diorganopolysiloxane oil is a compound having the formula ##STR8## wherein R 3  and R 4  are monovalent substituted or unsubstituted hydrocarbon groups, and a has an average value of from 1 to 1,000. 
     
     
       4. A composition according to claim 3, wherein R 3  and R 4  are selected from the group consisting of alkyl groups, and aryl groups. 
     
     
       5. A composition according to claim 3, wherein R 3  and R 4  are selected from the group consisting of methyl and gamma, gamma, gamma-trifluoropropyl. 
     
     
       6. A composition according to claim 1, wherein X is an ion selected from the group consisting of calcium ion and sodium ion. 
     
     
       7. A method of using an electrorheological fluid composition which comprises applying an external electric voltage to the electrorheological fluid composition, the improvement comprising using as the electrorheological fluid the composition of claim 1. 
     
     
       8. An electroviscous fluid composition comprising: (I) an electrical insulating fluid selected from the group consisting of mineral oils, dibutyl sebacate, chloroparaffins, fluorine oils, and silicone oils;   (II) an organopolysiloxane compound having the unit formula ##STR9##  wherein R 1  is C 1-20  alkyl or aryl, R 2  is C 1-20  alkylene, X is a monovalent or divalent metal ion, l, m, p, and q are zero or greater than zero, and n is 1 or 2 with the proviso that p and q cannot simultaneously be zero; and   (III) a polyether.   
     
     
       9. A composition according to claim 8, wherein the polyether is a hydroxyl-terminated polyether. 
     
     
       10. A composition according to claim 9, wherein the hydroxyl-terminated polyether is a hydroxyl-terminated polyethylene glycol. 
     
     
       11. A composition according to claim 8, wherein the silicone oil is a diorganopolysiloxane oil. 
     
     
       12. A composition according to claim 11, wherein the diorganopolysiloxane oil is a compound having the formula ##STR10## wherein R 3  and R 4  are monovalent substituted or unsubstituted hydrocarbon groups, and a has an average value of from 1 to 1,000. 
     
     
       13. A composition according to claim 12, wherein R 3  and R 4  are selected from the group consisting of alkyl groups, and aryl groups. 
     
     
       14. A composition according to claim 12, wherein R 3  and R 4  are selected from the group consisting of methyl and gamma, gamma, gamma-trifluoropropyl. 
     
     
       15. A method of using an electrorheological fluid composition which comprises applying an external electric voltage to the electrorheological fluid composition, the improvement comprising using as the electrorheological fluid the composition of claim 8.